In 2002, a geophysical survey — part of a programme to survey the entire Orkney World Heritage Site — revealed a cluster of sub-soil anomalies, “indicative of settlement”, covering an area of 2.5 hectares on the south-eastern end of the Ness of Brodgar.
The sheer concentration of anomalies, and the variation, astonished the archaeologists.
In April 2003, a large, notched, stone slab was ploughed up. Initially thought to be part of a Bronze Age burial cist, the possibility that human remains had been disturbed led to a rescue excavation by Beverley Ballin-Smith and Gert Petersen, from the Glasgow University Research Division.
Following the discovery of what we now refer to as Structure One, a resistivity survey was carried out to try to define the extent of the built archaeology and complement the initial gradiometer survey.
The results confirmed that something large and complex lay under the soil, so further investigations began.
To examine the nature, depth and extent of these suspected archaeological deposits, eight test-trenches were placed across the site in 2004.
They confirmed that much of the mounded ridge on the south-eastern end of the Ness is artificial – made up of structures and middens all dating from the Neolithic.